紫外光谱在线监控动态微波辅助萃取半枝莲中的野黄芩苷

建立一种动态微波辅助萃取方法, 用于萃取半枝莲中的野黄芩苷. 应用紫外光谱对整个过程在线监控, 实现了整个萃取过程的可视化. 用正交实验优化微波萃取条件. 实验结果表明, 所建立的方法可以防止被测物的分解, 减少萃取时间和溶剂的消耗. 野黄芩苷的质量浓度采用高效液相色谱进行离线测定, 得到的检出限和定量测定下限分别为028 mg/L和093 mg/L, 日内和日间精密度(RSD)分别为1.7%和3.6%, 平均加标回收率为98.3%.

On-line Monitoring of Dynamic Microwave-assisted Extraction of Scutellarin from Scutellaria barbata by UV Spectroscopy

A dynamic microwave-assisted extraction ( DMAE) approach was established for the extraction of scutellarin from Scutellaria barbata. The overall extraction process was monitored by on-line measuring the UV absorbance of the extract. The extraction conditions were optimized using orthogonal experimental design. The content of scutellarin was off-line analyzed by HPLC. The detection and quantification limits of scutellarin obtained were 0.28 mg/L and 0.93 mg/L, respectively. The within-day and between-day precisions (RSD) were 1. 7% and 3. 6% , respectively. The mean recovery of scutellarin was 98. 3%. The DMAE was compared with Soxhlet extraction and pressurized MAE ( PMAE) respectively. The results show that the dynamic method is superior to PMAE in preventing analyte degradation, and also to soxhlet extraction in the reduction of time and solvent required. It is more important that the extraction process can be visually observed by UV on-line monitoring.